Japanese Patent Application Publication 54-84,525 (1979) describes a process for the production or 6-aminocapronitrile (6ACN) and caprolactam (CL) by treating molten polycaproamide (nylon 6) at elevated temperature (340.degree. C.) and pressure (6 kg/cm.sup.2) with ammonia gas. British Patent 1,172,997 discloses conversion of a polyamide into monomeric compounds by heating the polyamide with ammonia in the presence of hydrogen and a hydrogenation catalyst. The patent exemplifies the process with polyhexamethylene adipamide (nylon 6,6) and with nylon 6. With nylon 6,6, the products are hexamethylene diamine (HMD) and hexamethyleneimine and a small amount of unidentified material. When using nylon 6 in accordance with the patented process, one is said to obtain HMD, hexamethyleneimine and N-(6-aminohexyl)-hexamethyleneimine. It is an object of the present invention to obtain a mix of monomers from nylon 6,6 or a mixture of nylon 6,6 and nylon 6 which can be used for reconversion into useful polyamides or for other purposes.